The present invention relates to technology effective when applied to device structure technology of a reverse conducting IGBT (Insulated Gate Bipolar Transistor).
International Publication No. 2004-109808 Pamphlet (Patent Document 1) or United States Patent Publication No. 2009-68815 (Patent Document 2) corresponding thereto discloses a reverse conducting IGBT that incorporates a fly-back diode by forming a plurality of stripe-shaped N-type impurity regions via an embedded insulating film between the N-type impurity regions and a P-type collector region on the back side of the device.
Japanese Patent Laid-Open No. 2007-288158 (Patent Document 3) or United States Patent Publication No. 2008-315248 (Patent Document 4) corresponding thereto discloses a reverse conducting IGBT that incorporates an FBD by forming a plurality of stripe-shaped N-type impurity regions in a P-type collector region on the back side of the device.
United States Patent Publication No. 2008-135871 (Patent Document 5) discloses a reverse conducting IGBT which incorporates an FBD by forming dot-shaped N-type impurity regions in the shape of a lattice in a P-type collector region on the back side of the device and which partially provides a part where the dot-shaped N-type impurity region dos not exist.
“1200V Reverse Conducting IGBT”, by Takahashi and three others, Proceedings of 2004 International Symposium on Power Semiconductor Devices & IC's, Kita-Kyushu (Japan), pp. 133-136 (Non-Patent Document 1) discloses technology of a reverse conducting IGBT that incorporates an FBD by forming a plurality of stripe-shaped N-type impurity regions in a P-type collector region on the back side of the device using thin film wafer processing technology.